In some embodiments, vibration and noise control systems utilize force generators (FGs) to actively eliminate or reduce the effect and impact of unwanted vibratory disturbances on a system. Vibration disturbances can wreak havoc on systems by reducing the life expectancy of the systems, structurally damaging the systems, and/or reducing the overall system performance. These impacts create potentially unsafe conditions when the systems are used.
Implementing active vibration and noise control (e.g., via FGs) is increasing and often preferred over implementing passive vibration control (e.g., via passive dampers or absorbers), in some aspects, to reduce the overall system weight. Some active vibration control systems (AVCS) are also an increased safety risk for some systems, as some AVCS are safety-critical systems. Safety-critical systems are those systems whose failure could result in loss of life, property, and/or damage to the environment. AVCS become safety-critical, for example, when the vibrations being cancelled have the ability to critically impact operations or by putting life or property at risk should a failure of the AVCS, or portions thereof, occur.
One non-limiting example of an AVCS that is a safety-critical system is in the aviation field, where active vibration control is used to mitigate vibrations having damaging effects on different systems (e.g., rotor(s), propeller(s), stator(s), engine(s), gearbox(es), etc.) and/or avionics. Other negative impacts from vibration in the aviation field include damage inflicted to human occupants and/or cargo. Other exemplary systems that may be negatively impacted by exposure to vibration forces include industrial equipment and manufacturing structures, buildings, vehicles (e.g., automobiles, avionics, aerospace), transportation, maritime structures, and/or any other structure or system subjected to an unwanted or potentially damaging vibratory input. The negative impacts can vary per situation.
One problem with current AVCSs is the inability to adequately detect system problems (e.g., failures or faults) and actively and/or autonomously adjust appropriately to handle failure modes for safety-critical systems. For example, one safety-critical system in the aerospace field impacts aerospace certification due to loss of function and/or an erroneous function. In this example, loss of function refers to an AVCS failure where it stops providing vibration control. In this same example, erroneous function refers to failure modes where the force output of the FGs is not a desired output or the FG erroneously induces vibration that is not wanted. Other examples include hydroelectric turbines, fast spinning industrial equipment, propulsion systems, and/or any other system or structure where the failure of a vibration control system has a damaging or catastrophic effect. Further problems with current AVCS include a lack of redundancy while minimizing weight and space penalties on the systems being controlled.
Accordingly, there is a need for lighter weight AVCS and methods that are redundant, safety-critical, and configured to implement autonomous vibration control.